Power-transmission mechanism.



D. NETTENSTROM.

POWER TRANSMISSION MECHANISM.

APPLICATION FILED APR. 3, 1911,

Patented Mar. 18, 1913 2 SHEETS-SHEET l.

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DAVID NETTENSTBOM, or cnrcaeo, ILLINOIS, assrenon or ONE-HALF 'ro CHARLES H. EDER, or CHICAGO, ILLINOIS.

POWEBTRANSMISSION MECHANISM.

Specification of Letters Patent.

Patented Mar. 18, 1 913.

Application filed April 3, 1911. 7 Serial No. 618,678.

anism, of which the following is a specification, reference being had to the accompanymg drawings, forming a part thereof.

The purpose of this invention is to provide an improved mechanism for powertransmission mechanism, particularly adapted for use whcre'sudden variation of speed or load, and also ready reversal of direction must be provided for.

It consists ofthe features and elements shown and described as indicated in the claims.

In the drawings: Figure 1 is an airial section of a, gear train and its mountings.

embodying this invention. Fig. 2 is a detail elevation of a detached portion of the structure comprising a fixed bridge and friction idler wheels journaled therein. Fig. 3 is a sectional view showing in elevation the gear, D and the actuating arms for the clutch, 12, and brake band. 14:. Fig. 4 is a detail of a clutch shifting device.

The operation of this device may be most readily understood by the consideration of the well lznown laws governing the operation of differential gear train. Iteferring Fig. l, the differential gear train contained in this particular transmission mechanism consists of the driving wheel, A, the driven wheel, B, and the beveled gear idlers, C, connecting them. The driving gear wheel, A, is keyed rigidly to the extended portion, 1, of the engine shaft, while the driven gear, B, is adapted for operative connection with the driven shaft, 52, by means of a sliding jaw clutch, 3, or any other suitable connection. The idlers, C, are journaled between a drum, D, and a hub, 4, loose'lymounted on the shaft, 1. One end of the cylindrical drum. D, has out upon it a crown gear, D meshing with bevel gears, 5, jonrnaled fixedly in the casing, 63, and operatively connecting the said drum, D, with a gear, 7 formed on the friction disk, 7. The disk. 7, is carried loosely upon the shaft. 1, and is adapted to be rotated through the operation of the friction idler wheels, 8, which contact with an opposite and similar disk, 9, secured to the shaft, 1. by means of the feather, 1 and held in contact with the idler wheels by a spring,

.10, which reacts against an adjustable collar, l0 on'the shaft. Considering now, the differential. gear train, composed of the elements, A, B, Q, and D, it is well known that if the drum,D. be held stationary while the shaft, 1, is revolved in a given direction, the result will be a rotation of the gear Wheel, B, at a speed equal to that of the gear wheel, A, but in the opposite direction. It will also be seen that if the drum, D, be revolved at the same annular velocity and in the same direction as the shaft, 1, the result will he no differential motion whatever between the gear, A, and the idlers, G, the elements, A, C, and D, acting merely as a jaw clutch to drive the gear. B, in the same direction and at the same velocity nith themselves. The third condition which may be considered, is that in which-the gear, B. is held stationary while the shaft. 1,. and its rigid gear wheel, A, are revolved and in which case the result is a revolution of the drum, D, in the same direction as the shaft, 1, but at one-half its angular velocity. Conversely the rotation of the drum. D, in

the same direction as the shaft, 1, but at one-half its angular velocity would result in no rotation of the gear, 13-.

In the present invention. the foregoing= well known principles have. been applied to accomplish the gradual variation ofthe speed of the driven shaft, 2, from Zero up to the speed of the driving shaft, 1. with a possibility of even a higher speed than that of the driving shaft, together with the opportunity for reversing the direction of rotation of the shaft, 2, and of varying its speed in such reverse direction. Briefly this is accomplished by varying the speed of the drum, D, the latter being driven through a variable speed friction transmission mechanism from the driving shaft, 1.

'VVith the idler wheel, 8, set as shown in Fig. l, the friction disk, 7, would obviously run at a speed somewhat lower than that of the disk, 9, and this speed would. be further reduced through the gear, 7, idlers, 5, and crown gear, D, with the. result that the angular velocity of the drum, D, would be just one-halt that of the friction disk, 9, and its driving sl'iailt, 1. Ren'ienibcring that the gear. A, is keyed fast to the driving shaft, 1, it will be seen that with the parts in this position, the third of the three conditions above recited would be present, that is, the driven gear, B, would remain stationary. It the idler wheels. 8, he turned to the position indicated by line, X-X; on F 1, it is obvious that the disk, 7, would receive at a speed somewhat greater than that of the disk, 9, but owing to the particular proportions. of the gears, 7 and D, this gain of angular velocity is just neutralized by the said gears so that the angular velocity of the gear. D, and its drum, D, is reduced to a value just equal to the angular velocity of the disk, 9, and its driving shaft, 1. The direction of rotation having been twice reversed, the drum, D, will rotate in the same direction as the driving, shaft. 1. The gear, A, being rigid with the shaft. 1, and consequently revolving with it, it may be seen that the resulting condition is that of the second case above recited, that is, the parts, A, C, and D, will act together as a jaw clutch for driving the gear, B, with them at the same velocity and in the'same direction. Since this position of the train would probably be the most used, it is found convenient to provide an auxiliary clutch, 11, carried on short feathers, A projecting t'rorn the hub of the gear, A. and provided with a cone face, 11, adapted to trictionalljv engage the interior surface, D of the drum, D. Thus, when the condition of equal velocity of the driving shaft, 1. and the driven shaft, 2. has been attained, it may he maintained by throwing into service this clutch which connects the drum, D, more or less positively to the shaft, 1, and relieves the iriction disks and idlers of any driving strain. The engagement of the clutch, 1.1. with the drum, D, isv etlectcd through a partial rotation of one of the elements of the shifting device, 12, shown in detail in Fig. l and which consists oit the two annular elements, 12' and 12*, the former of which is rendered stalilOlTifll'YWYli'l'l the 0- no", 6, by means of its lugs, 12, projecting into the hub, 13, which serves as a partial. support for the idlers. 5. The opposing faces of the annular elements, 12 and 12, respectively, are formed with coii 'ierating projections, resembliiu: ratchet:

teeth, byvirtue of which the thickness of the said elements varies from point to point about their circumferences. With these opposing faces in contact, a slight rotation of the element, 12", with respect to the elemeat, 12*, will cause the former to more short distance along the shaft, 1, and by such movement to force the cone clutch, 11, into engagement with the drum, D. A. rocker arm, 12, extending radially from the element, 12", isadapted for connection with any suitable operating means which might be arranged for actuation automatically, soon as the idler wheels, 8, were brought into the position indicated by the line,

L&X, or which could be arranged for actuation at will, if preferred. It will be understood that the range of movement of the rocker arm, 12, would not exceed the angular extent of one of the ratchetdike projections on the face of the annulus, 12". The clutch, 1, would be released by returningthe rocker arm, 12, to its original position, viz: that shown'in full lines in Fig. 3. With this support removed, the clutch would :radily slip out of engagement with the drum, as soon as the friction wheels, 8, were moved to a position which would cause the drum, D, and the 'gear, A, to be driven at different speeds.

As the idler wheels, 8, are turned from their position at the line, X X, to the neutral position in which they are shown in full lines in Fig. 1. the speed of the driven shaft. 2-, willgradually be decreased from the speed of the engine shaft down to zero, in which instance the drum will be revolving with one-half the angular velocity oi the engine shaft and in the same direction. It the idler wheels, 8, be turned still further and past this neutral position, the speed of the drum, D, will gradually be decreased still further with a resulting rotation of the driven shaft, 2, in the opposite direction and at a gradually increasing rate. If, as the velocity of the drum, D, approached zero. it should be clamped and held stationary. the first of the three above recited conditions would obtain in the differential gear train and the driven shaft, 2, would revolve at the same speed as the driving shaft, 1. but in the opposite direction. In the use for which this transmission is primarily designed, namely, for use in self-propelled ve hicles, this condition would not often obtain, since it would hardly ever be desired to drive the vehicle backward at as high a rate of speed as would result in this case. However, since the reduction of the speed of the driven shaft, 2. from .a value equal to the speed of the driving shaft, 1, down to the value of Zero, is obtained by reducing the speed of the drum, D, the brake band, l t. positioned about the druiii, D, becomes a very effective instrument for reducing the speed ot the driven shaft, 2, and (in the case of an automobile) for bringing the ve hicle to a stop, since it serves to rapidly reduce the speed at the drain, D, to a; value of? one-halt weed of the engine Ti,-

and even lower than this, i it necessary to reverse the driv ing the vehicle in order to bring it to promptly. This brake band, it, is shown as of the usual construction with its ends connected respectively to the two arms of the bell crank lever, 15, provided with an operating arm, 15 and any suitable operating connections not shown.

Fig. 2, illustrates the particular arrangement of parts by which the friction idlcrs S are supported within the casing. The tour armed spider 16, having an interrupted rim formed by the portions 16. furnishes support for these idler wheels. Between the consecutive arms of the spider, there are mounted carriers o connected to the spider arms by short swivel shafts, 8*, which are each provided with segn'iental bevel gears 8. These gear segments are positioned so as to mesh in pairs, and in this way, since the swivel shafts are tight in their respective carriers 8, an} rotation of one of the carriers about its swivel axis, causes a similar rotation of r, all the carriers. One of the swivel shafts is sufficiently elongated to extend outside the casing and has a rocker arm 8", designed for connection with any convenient form of operating means. The lugs 6", formed on the innensurface of the casing retain the rim portion of the spider against axial movement, and the lugs 6", prevent it from slipping circinnterentiallv within the casing. In order to minimize as far as possible the losses due frictii'in in this power transmission, all bearing and wearing surfaces are provided with ball or roller bearings of the usual types. The shaft 1, is provided at its entrance to the case 6, with a ball bearing 1* of the annular type, while the spider 16, the friction disk 7, stationary hub member, 13, the huh l and the elongated hub B of the driven gear 3, are each provided with sets of ller bearings indicated respectively at 1.1, 4, and B his last mentioned roller hearing serves also for the abutting end of the driven shaft 2 for which there also shown another set of roller hearings 2 carried in an extended portion 6 of the casing.

Annular ball bearings B journal the driven gear B, and a thrust bearing is interposed between this gear and the casing, in order to take up axial thrust. which is be found wheel of incident to all such diil'erential gearing. l n connection with the differential gear train there are alsoprovided thrust bearings, .2 and a, the first two of which not also as spacers for causing the gears to mesh prop-- erly. The ball thrust plate 11 is interposed between the clutch 11 and the clutch shifter 12 to minimize the friction of these parts, resulting when the clutch is thrown into operative position by the shifter. The heavy rest more thrust which results from the action of the spring 10, forcing the friction disks 7 and 'Qinto driving contact with the idler wheels 8 is prevented from passing along the shaft bevond the disk I h v a double thrust bearing T" lut prised between the rear-face of the hub of the dish I. and the shoulder 1 formed on the sha't't, The remaining thrust bearing is located between th 13 and one. plate of the l. earing T", as i. iown at 13. The bevel idlers C, are journaled on short studs C, provided each with a set of balls C which receive the thrust resulting from the well known action of bevel gears. Exactly similar bearings are shown at in connection with the idler gears The friction wheel idlers S aremonnted in plain bearings but are set between ball thrust hearings, since there is considerable side strain on the idlers, as they are turned from one position to another about their swivel shafts S.

I claim 1* 1. A power transmission mechanism, comprising a driving and a driven shaft, a differential gear train connecting said shafts, a carrier for the idler gears of said train mounted for rotation about the common axis of the initial and final gears, a disk secured to the driving shaft, a second and similar dish loosely mounted upon said shaft, positive direction-reversing connections between the carrier and said looselv-mounted disk, specdwaryin f. directionreversing connec- Lap-- carrier for the idler gears of said tram cun l for rotation about he. common axis he inii'ir i d transin ion gearing. comprising a Air of dislcs, one of which is mounted for rotation with the driving shaft, the other being loose thereon and operatively connected with the carrier, and adjustable friction i wheels mounted between the opposing faces of the disks, in contact therewith and including in range ofadjustment a position torrevolving the carrier at one half the rate of revolution of the driving shaft.

A power transn'iission' mechanism, com- 1, of t ed final gears, and a variable prising a driving and a driven shaft, a dif- "ierential ear train connecting said shafts, a -arrier for the idler gears of said train mounted for rotation about the common axis a of the initial and final gears, a dish mounted on the driving shaft for rotation therewith, I a second dish ]O111I1t1il loosely thereon, l positive speed-reducing connections between [the second dish and the carrier, and fricl tional speed-varying devices between the two tions between tie two disks, and a clutch disks, the speed-reducing connections being I In testimony whereof I have hereunto setso proportioned that the adjustment of the my hand at Chicago, Illinois this 1st day of 10.

April, 1911.

DAVI i) NPYITTI E NSTROh i.

speed-varying Connections shall accomplish a variation in the speed of the carrier, rang- 5 ing from a value less than half of the rate of revolution of the driving shaft up to a Witnesses:

value greater than the said rate of revolution LUCY I. S'roNn,

of the driving shaft. M. GERTRUDE Am. 

